This weekend I plan to remove the stock mach 460 setup from my 03 roush. I am installing a pioneer deh-2500ui with pioneer 2-ways in the door and rear deck. I am installing one of the sub boxes built to go under the rear deck but that mean the amp rack has to be removed. I want to keep all speakers including the door tweeters. I was wondering what all I need to run new wires for. Can I use the wires running into the amp in the rear to run the rear deck speakers. Also is there any way that I can wire the signal wire that comes out where the head unit is and wire it to the amp output wire. Or do I need to just run new wires from the head unit to the door speakers? I tea that the tweeters will work with the amp rack removed. Is that correct? I definitely want to get rid of the amps though and keep all speakers. Just need to know what all I have to wire.
I think that you will need to run new wires to all of the speakers if you are going to remove the Mach 460 amps. There are afew writeups on replacing and upgrading the Mach systems. You need to be aware that Ford used 8 ohm speakers in the Mach systems also. I replaced my 460 head unit with a Kenwood KVT-516. I read the stuff I found on the GOOGLE.Some said it can't be done. Others gave compliccated instructions on modifying harnesses. The best way to do it is to go to Crutchfield.com, enter your car details and then select your head unit from their inventory along with your amps. Crutchfields web app will tell you what harnesses and other adaptors you need and warn you of any incompatabilities or modifications required. If you buy the harness zand /or other components from Crutchfield, they will send you instructions on installation and provide support if needed. I think you are probably going to have to replace the speakers if you go with new amps. I'll get those Mach 460 links when wifey gets off my computer. Posting this from my Nook.
The mach system is different than most car stereo systems. To keep your speakers, you will need a device to match impedance between the existing stuff and your new stuff. You should be able to use your existing wires with available adapters, or if you are not planning on returning it to stock, just cut off the current connecters.